A systems analysis of medical care delivery is proposed, making use of the key relationships: (1) a generalized demand for medical care, based on the individual's health status and demographic characteristics price of care, travel time and cost, and waiting time; (2) the efficacy of each delivery institution based on its staffing and resources (physician time and ancillary services) given to each patient and on the initial health status of the patient; (3) a referral matrix for each institution, based on its efficacy, and initial health status of patients; (4) a patient compliance matrix, based on end health status and demographic characteristics of each patient's generalized cost of getting additional care, the institution referred to, and the time until the appointment; and (5) the health status distribution in the population, based on its demographic characteristics, public health, and the care received from the delivery system. The output of the model consists of the equilibrium health status distribution of the population, the cost of the delivery system, and the resources used in the delivery system. This model is simulated and the changes in equilibrium stemming from parameter changes investigated. Proposed work consists of: (1) estimation of the model's parameters using 12 surveys undertaken by NORC under OEO sponsorship in 1968-71 to investigate the health behavior of the poor; (2) estimation of the model's parameters from a review of the literature on health status and utilization, as well as an investigation of this literature to find suggested alterations in the model; (3) modification of the model and its parameters to take account of what is learned in the first two steps; and (4) investigation of the implications of proposed policy changes that would modify the financing of medical care, the institution's delivery care, or other aspects of the system.